1. Field of the Invention
The present invention relates in general to rotary hones of a type suitable for polishing the walls of cylinders in mechanical apparatus, and it relates in particular to a rotary hone having the capability of being conveniently assembled during manufacture.
2. Description of the Prior Art
In mechanical apparatus incorporating a piston and cylinder arrangement, it is frequently necessary or desirable to resurface the wall of the cylinder such that the piston assembly can form a proper seal with the cylinder wall as it reciprocates therewithin. One such apparatus utilizing a piston and cylinder arrangement, for example, is a disc brake caliper. The piston, which is mechanically connected to a vehicle braking mechanism, is movable within the caliper under the action of fluid pressure. With continued use, the cylinder wall of the caliper can become pitted or scored due to the effects of heat and corrosive action of the fluid contained therein. In servicing the brake system of a vehicle having a worn caliper, it is often possible to remove the surface irregularities in the cylinder walls of the caliper through the use of a simple rotary hone. The caliper assembly can thereby be fitted with new piston seals such that it functions as originally manufactured.
A cylinder hone which has proved particularly effective in resurfacing of disc brake calipers is disclosed, for example, in U.S. Pat. No. 3,005,294, issued to Kushmuk on Oct. 24, 1961, and assigned to the assignee of the present invention. Typically, such a hone comprises a plurality of abrasive units each carried by a pivotal arm extending from a central body member which, in turn, is connected to an elongate drive shaft. The drive shaft is dimensioned to be inserted into the chuck of a standard rotary drill such that the hone may be rotated wthin the cylinder at sufficient speeds to resurface the cylinder wall within a short period of time.
Although cylinder hones of the foregoing general description are well known, it would be desirable to simplify their construction so that they can be more economically manufactured, thereby reducing their cost. One of the manufacturing steps which adds considerably to the cost of manufacturing a cylinder hone is in connecting the abrasive unit arms to a central support member from which the drive shaft extends. Since the arm must be biased outwardly in a pivotal arrangement from the central support member, typical hone structures include individual pin members for connecting the arms to the body member. Installing such pins during assembly of the hone is a manual operation involving considerable manufacturing time thereby adding substantially to the cost of the completed assembly.